Fire-and electromagnetic interference (emi)-resistant aircraft components and methods for manufacturing the same

ABSTRACT

Fire- and electromagnetic interference (EMI)-resistant aircraft components and methods for manufacturing the same are provided. A fire-and EMI-resistant aircraft component includes an article comprised of a polymeric material. A fire-retardant material layer overlies the article. A thermally and electrically conductive coating material layer is disposed intermediate the article and the fire-retardant material layer. Optionally, at least one continuous electrically conductive element is integrated with the polymeric material of the article.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.14/081,009 filed on Nov. 15, 2013. The relevant disclosure of the aboveapplication is incorporated herein by reference.

TECHNICAL FIELD

The present invention generally relates to aircraft components and theirprotection against certain hazards, and more particularly relates tofire- and electromagnetic interference (EMI)-resistant aircraftcomponents and methods for manufacturing the same.

BACKGROUND

Aircraft components may be exposed to risks from certain hazards, suchas fire and/or electromagnetic interference (EMI). For example, certainaircraft components may be used in an aircraft “fire zone”, i.e., in anaircraft compartment that contains ignition sources and the potentialfor flammable fluid leakage. Some aircraft components may be equippedwith electronic devices that can be harmed or disrupted byelectromagnetic interference (EMI). Electromagnetic interference (EMI)is caused when electronic devices exhibit interference on otherelectronic equipment in their vicinity, causing negative consequencessuch as degradation or even malfunctioning. For example, EMI can lead toerased data, loss of connectivity for computers and cellphones, as wellas more serious effects like the jamming of cockpit radios and radarsignals that could ultimately hamper communication between an aircraftpilot and respective radio tower. A lightning storm is one source ofEMI.

Conventional systems and methods for providing fire resistance toaircraft components include using thermal blankets and/or fire shieldspositioned around the component. Components can also be shielded toprotect against EMI. Unfortunately, these blankets and shields addsignificant weight and space requirements. Where space is too limited,they cannot be used at all. Some aircraft components are designed withfire-retardant coatings, but these coatings can fail to protect acomponent from fire and do not offer any protection against EMI. This isespecially true for non-metallic aircraft components.

Accordingly, it is desirable to provide fire- and EMI-resistant aircraftcomponents and methods for manufacturing the same. In addition, it isalso desirable to provide lightweight and effective integral andconformal fire- and EMI shielding materials for non-metallic aircraftcomponents. Furthermore, other desirable features and characteristics ofthe fire- and EMI-resistant aircraft components and methods formanufacturing the same will become apparent from the subsequent detaileddescription and the appended claims, taken in conjunction with theaccompanying drawings and the preceding background.

BRIEF SUMMARY

Methods are provided for manufacturing a fire- and electromagneticinterference (EMI)-resistant aircraft component. In accordance with oneexemplary embodiment, a method for manufacturing a fire- andEMI-resistant aircraft component comprises forming a conductive coatingmaterial layer on at least a portion of an intermediate articlecomprised of a non-metallic material. The coating material layer iselectrically and thermally conductive and comprised of metal. Afire-retardant material layer is cold-sprayed on the conductive coatingmaterial layer.

In accordance with another exemplary embodiment, a method formanufacturing a fire- and EMI-resistant aircraft component comprisesforming an additive-manufactured intermediate article comprising apolymeric material. A thermally and electrically conductive coatingmaterial layer is applied on the additive-manufactured article forming acoated article. The thermally and electrically conductive coatingmaterial layer comprises a metal. A fire retardant material layer iscold sprayed on the coated article.

In accordance with another exemplary embodiment, a fire-andEMI-resistant aircraft component is provided. The fire- andEMI-resistant aircraft component comprises an article comprised of apolymeric material. A fire-retardant material layer overlies thearticle. A thermally and electrically conductive coating material layeris disposed intermediate the article and the fire-retardant materiallayer. Optionally, at least one continuous electrically conductiveelement is integrated with the polymeric material of the article.

Further provided is a fire-and EMI-resistant aircraft component, whichincludes an article comprised of a polymeric material having a first endand a second end. The component includes a fire-retardant material layeroverlying the article and a conductive coating material layerintermediate the article and the fire-retardant material layer. Thecomponent includes at least one continuous electrically conductivefilament integrated within the polymeric material of the article thatextends through the article from the first end to the second end toprovide a conduction path through the article.

Also provided is a fire-and EMI-resistant aircraft component, whichincludes an article comprised of a polymeric material having a first endand a second end. The component includes a fire-retardant material layeroverlying the article, and a conductive coating material layerintermediate the article and the fire-retardant material layer. Theconductive coating material layer is applied locally to portions of thearticle. The component includes at least one continuous electricallyconductive filament integrated within the polymeric material of thearticle that extends through the article from the first end to thesecond end to provide a conduction path through the article.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will hereinafter be described in conjunction withthe following drawing figures, wherein like numerals denote likeelements, and wherein:

FIG. 1 is a cross-sectional view of a fire- and EMI-resistant inletduct, an exemplary aircraft component manufactured by the methodsaccording to exemplary embodiments;

FIG. 2 is a flow diagram of a method for manufacturing fire- andEMI-resistant aircraft components, according to exemplary embodiments ofthe present invention;

FIG. 3 is a cross sectional view of a portion of a fire- andEMI-resistant aircraft component, such as the inlet duct of FIG. 1;

FIG. 4 is a cross sectional view of a portion of a fire- andEMI-resistant aircraft component, according to another exemplaryembodiment of the present invention; and

FIG. 5 is a schematic diagram of a conventional FDM additivemanufacturing process.

DETAILED DESCRIPTION

The following detailed description is merely exemplary in nature and isnot intended to limit the invention or the application and uses of theinvention. As used herein, the word “exemplary” means “serving as anexample, instance, or illustration.” Thus, any embodiment describedherein as “exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments. All of the embodiments describedherein are exemplary embodiments provided to enable persons skilled inthe art to make or use the invention and not to limit the scope of theinvention which is defined by the claims. Furthermore, there is nointention to be bound by any expressed or implied theory presented inthe preceding technical field, background, brief summary, or thefollowing detailed description.

Various embodiments are directed to fire- and EMI-resistant aircraftcomponents and methods for manufacturing the same. The definition of theterms “fire-resistant” or “fire-resistance” as used herein means thecapacity to perform the intended functions under the heat and otherconditions likely to occur when there is a fire at the place concerned.Aircraft components are demonstrated to be fire resistant by meeting therequirements of a flame exposure test. Therefore, the aircraftcomponents manufactured by the methods according to exemplaryembodiments meet the requirements for the flame exposure test and aretherefore deemed “fire-resistant.” The flame exposure test requires thatthe aircraft component has the ability to withstand a 15 minute keroseneburner test. The term “aircraft components” as used herein includes gasturbine engine components and other components located within anaircraft, at least a portion thereof requiring fire-resistance (i.e., acomponent that needs to pass the flame exposure test to be put intousage), EMI resistance (i.e., a component equipped with an electronicdevice that can be harmed or disrupted by EMI), or both fire-andEMI-resistance. The term “aircraft components” includes, for example,mounts, cases, brackets, ducts, inlets, sheet or structural members,fluid-carrying lines (e.g., piping), fluid system parts, wiring,fittings, and powerplant controls. Aircraft interiors and structures canalso be made fire- and EMI-resistant. As used herein, a “fire- andEMI-resistant aircraft component” means that that the entire componentor at least a portion thereof, is fire- and EMI-resistant.

As noted previously, the aircraft component may be used inside oroutside of an aircraft fire zone, i.e., an aircraft compartment thatcontains ignition sources and the potential for flammable fluid leakage.Such compartments are classified as “fire zones.” For example, theengine case around the compressor, combustor, and turbine sections ofthe engine define a fire zone. The gearbox and its accessories are alsoconsidered potential ignition sources during failure conditions thatcould cause temperatures to exceed the auto ignition temperatures offluids that may be present in the compartment. The APU compartment is bydefinition a fire zone. There are other fire zones aboard an aircraft.In accordance with exemplary embodiments, imparting fire-resistance alsoimparts electromagnetic interference (EMI) resistance.

Referring to FIGS. 1 and 3, according to exemplary embodiments, thefire- and EMI-resistant aircraft component 10 comprises an intermediatearticle 12 and a fire-retardant layer 16 with a thermally andelectrically conductive coating material layer 14 between theintermediate article and the fire-retardant layer. This type of coatingsystem is called a “sandwich” coating system because the thermally andelectrically conductive coating material layer is bound between twostructures—the intermediate article 12 and the fire-retardant materiallayer 16. The sandwich coating system is used here because- thefire-retardant layer (also known as a “thermally resistant layer) mustbe on the outside surface for maximum protection.

Referring now to FIG. 2, in accordance with exemplary embodiments, amethod 100 for manufacturing a fire- and EMI-resistant aircraftcomponent, such as the inlet duct of FIG. 1 (identified as an exemplaryfire- and EMI-resistant aircraft component 10 ), begins by providing theintermediate article 12 (step 110 ). The intermediate article 12comprises a non-metallic material of polymer or composite construction.Suitable exemplary polymers (polymer materials) include natural andsynthetic rubber, polymer resins, polyimides, polyether ether ketones(PEEK), cyanate esters, bismaleimids (BMI), neoprenes, nylons, polyvinylchlorides (PVC or vinyl), polystyrenes, polyethylenes, polypropylenes,polyacrylonitriles, polyvinyl butyrals (PVB), silicones, and many more.

“Composite materials” are defined as materials made from two or moreconstituent materials with significantly different physical or chemicalproperties, that when combined, produce a material with characteristicsdifferent from the individual components. The individual componentsremain separate and distinct within the finished structure. Suitableexemplary engineered composite materials include composite buildingmaterials such as cements, concrete, reinforced plastics such asfiber-reinforced polymers, metal composites, and ceramic composites(composite ceramic and metal matrices). Suitable exemplary fibers usedto reinforce the polymers in the fiber-reinforced construction includecarbon fibers (e.g., IM7, AS4, T300, etc.), fiber glass, Kevlar, andmany more. The non-metallic material comprises a non-fire-resistantmaterial (i.e., the non-metallic material does not pass the flameexposure test).

In one embodiment, the intermediate article 12 may be already availableand obtainable from commercial sources. For example, the intermediatearticle may comprise an already manufactured component that fails topass the flame certification test (i.e., the already manufacturedcomponent is non-compliant with the flame certification test and istherefore not fire-resistant). For example, the intermediate article 12may be part of old stock and rather than scrapping the non-compliantcomponent, a fire- and EMI-resistant component 10 may be manufacturedfrom the non-compliant component (here, the intermediate article) byperforming the forming and cold spraying steps 120 and 130 ashereinafter described.

In an alternative embodiment, the fire- and EMI-resistant component 10may be manufactured from an intermediate article 12 formed by anysuitable manufacturing process. For example, the intermediate articlecomprising the polymeric material may be formed by a known additivemanufacturing process. The polymeric material (a “build material”) maybe used in an additive-manufacturing process as known in the art to formthe intermediate article 12 from which the fire- and EMI-resistantcomponent 10 is manufactured. Additive Manufacturing (AM) is defined bythe American Society for Testing and Materials (ASTM) as the “process ofjoining materials to make objects from 3D model data, usually depositlayer upon deposit layer, as opposed to subtractive manufacturingmethodologies, such as traditional machining and casting.” Some examplesof additive manufacturing processes include: micro-pen deposition inwhich liquid media is dispensed with precision at the pen tip and thencured; selective laser sintering in which a laser is used to sinter apowder media in precisely controlled locations; laser wire deposition inwhich a wire feedstock is melted by a laser and then deposited andsolidified in precise locations to build the product; electron beammelting; laser engineered net shaping; and direct metal deposition . Ingeneral, additive manufacturing processes provide flexibility infree-form fabrication without geometric constraints, fast materialprocessing time, and innovative joining techniques. A finishing step maybe performed on the intermediate article formed by theadditive-manufacturing process. The finishing step may include, forexample, machining, etc. as long as the article is not exposed to heat.In some embodiments, the finishing step may be unnecessary and may beomitted.

In an additive-manufacturing process, a model, such as a design model,of the component may be defined in any suitable manner For example, themodel may be designed with computer aided design (CAD) software. Themodel may include 3D numeric coordinates of the entire configuration ofthe component including both external and internal surfaces of anairfoil, platform and dovetail. The model may include a number ofsuccessive 2D cross-sectional slices that together form the 3Dcomponent. Sequential deposit layers of build material (in this case,polymeric material) are fused and solidified according to thethree-dimensional (3D) model. Each successive deposit layer of theintermediate article may be, for example, between about 10 μm and about200 μm, although the thickness may be selected based on any number ofparameters.

In one exemplary embodiment, fused deposition modeling (FDM) may be usedto form the additive-manufactured intermediate article comprised of thepolymeric material. A schematic of a FDM process is depicted in FIG. 5.FDM is an additive manufacturing process that works on an “additive”principle by laying down material in layers; here, the polymericfilament 18 is unwound from a coil 20 (the “material cartridge in FIG.5) and is supplied through an extrusion nozzle 22 to form theintermediate article. The FDM process begins with a software processwhich processes an STL file (stereolithography file format),mathematically slicing and orienting the 3-D model for the buildprocess. The polymeric material is heated (by heater block 24 in FIG. 5)past its glass transition temperature and the molten polymeric materialis then deposited by an extrusion head, which follows a tool-pathdefined by computer-aided manufacturing (CAM) software, and theintermediate article 12 is built from the bottom up, one layer at atime. The filament of the polymeric material is unwound from the coiland supplied to the extrusion nozzle which can turn the flow on and off.The nozzle is heated to melt the polymeric material and can be moved inboth horizontal and vertical directions by a numerically controlledmechanism, directly controlled by the computer-aided manufacturing (CAM)software. The intermediate article is formed by extruding small beads ofthe polymeric material to form layers as the material hardensimmediately after extrusion from the nozzle. Stepper motors or servomotors are typically employed to move the extrusion head that includesthe extrusion nozzle.

Although the FDM additive manufacturing process is described herein forforming the intermediate article comprising a polymeric material, otheradditive manufacturing processes and other manufacturing processes ingeneral may be employed to form the intermediate article comprising thepolymeric material. The intermediate article comprising the compositematerial may be formed by conventional composite manufacturing processes(e.g., using composite ply lay-ups).

Still referring to FIG. 2 and now to FIG. 4, in an embodiment, the stepof providing the intermediate article further comprises optionallyintegrating a continuous electrically conductive element 26 into thesubstrate of the intermediate article to be formed (step 140). Thus, theintermediate article 12 and the fire- and EMI-resistant aircraftcomponent 10 a to be manufactured therefrom may further comprise thecontinuous electrically conductive element 26. The material for thecontinuous electrically conductive element comprises copper, aluminum,and their alloys, as well as combinations thereof. The term “continuouselectrically conductive element” as used herein refers to a thin,continuous elongate electrically conductive element generally and moreparticularly, comprises an electrically conductive wire which may be ofany cross-sectional shape such as circular, triangular, square,rectangular or polygonal or a like continuous element in the form of anelectrically conductive tape, ribbon, or the like. The continuouselectrically conductive element has an electrical resistivity of lessthan about 2.75 ohm/m at room temperature (70° Fahrenheit). Thecontinuous electrically conductive element may be in a spiral form toadd strength to the polymeric material or composite material in thevertical (Z) direction. The continuous electrically conductive elementprovides EMI-resistance to the fire- and EMI-resistant component 10 a tobe manufactured. In addition to providing EMI-resistance, the continuouselectrically conductive element 26 also provides a conduction paththrough the fire- and EMI-resistant aircraft component 10 a, therebypermitting transmission of a signal (e.g., a radio signal) from one endof the component to the other end of the component.

The continuous electrically conductive element 26 may be integrated intothe intermediate article 12 to be formed by integration with thenon-metallic material of the intermediate article to be formed. Forexample, when forming the intermediate article comprised of thepolymeric material by the FDM additive manufacturing process, theextrusion nozzle 22 (FIG. 5) incorporates a twin-arc or dual-arc weldingsystem with dual extrusion heads for simultaneously feeding thepolymeric material filament 18 and the continuous electricallyconductive element 26, i.e., in this example, the extrusion head mayinclude more than one nozzle to extrude the polymeric component materialto build the intermediate article and another nozzle to feed thecontinuous electrically conductive element through the intermediatearticle as it is being built. The continuous electrically conductiveelement extends from one end of the intermediate article to the otherend of the intermediate article.

The continuous electrically conductive element 26 may be integrated intothe intermediate article 12 comprising the polymeric material formed bymanufacturing processes other than by the FDM additive manufacturingprocess. The continuous electrically conductive element 26 may also beintegrated into the composite plies when forming a composite ply lay-up(not shown). As noted previously, the continuous electrically conductiveelement provides EMI-resistance and a conductive path to the fire-andEMI-resistant component 10 a to be manufactured. Additionally, thetensile strength of the fire- and EMI-resistant component 10 a to bemanufactured with the continuous electrically conductive element 26 isimproved relative to the tensile strength of the fire and EMI-resistantcomponent 10 that does not comprise the continuous electricallyconductive element.

Referring again to FIGS. 2 through 4, in accordance with exemplaryembodiments, the method 100 for manufacturing a fire- and EMI-resistantcomponent continues by forming a layer 302 of conductive coatingmaterial (hereinafter “a thermally and electrically conductive coatingmaterial layer”) on at least a portion of the intermediate articleforming a coated article (step 120). The thermally and electricallyconductive coating material layer has a thermal conductivity of greaterthan 175 W/m-K (watts/meters-Kelvin) at room temperature (70° F.) and anelectrical resistivity of less than about 2.75 ohm/m at roomtemperature. The thermally and electrically conductive coating materiallayer may be applied locally (“at least a portion”) or over the entireintermediate article 12. The thermally and electrically conductivecoating material layer is applied only where fire resistance is neededto avoid adding unnecessary weight. The thermally and electricallyconductive coating material layer 14 is comprised of a pure metal ormetal alloy. Suitable exemplary materials for the thermally andelectrically conductive coating material layer include copper, aluminum,combinations thereof, their alloys, and brass. The thickness of thethermally and electrically conductive coating layer may be from about 10μm to about 200 μm. The conductive coating material may be applied bycold-spraying techniques. Such techniques are well known in the art. Thecoating material may alternatively be applied by any known coatingtechniques such as, for example, chemical vapor deposition, plating, orthe like. As the thermal conductivity of the conductive coating materialis high (greater than 175 W/m-K), the thermally and electricallyconductive coating material layer acts to transfer heat away from thefire- and EMI-aircraft component. The thermally and electricallyconductive coating material layer also provides EMI resistance to thefire- and EMI-resistant component.

Still referring to FIGS. 2 through 4, in accordance with exemplaryembodiments, the method 100 for manufacturing a fire- and EMI-resistantaircraft component continues by thereafter cold spraying thefire-retardant coating 16 on the thermally and electrically conductivecoating material layer on the intermediate article (step 130). Thefire-retardant coating 16 may be applied by known cold-sprayingtechniques to a thickness of about 100 μm to about 700 μm. It ispreferred for the coating to be as thin as possible because of weightconcerns but still provide fire-resistance. The preferred density of thefire-retardant coating is about 98 to about 100 percent. Thefire-retardant coating comprises a fire-retardant material. Exemplaryfire-retardant materials include nickel-based alloys and superalloyssuch as INCONEL® alloys, ferrous-based alloys (e.g., stainless steel),cobalt-based alloys, and combinations thereof. Stainless steel is aferrous-based alloy with a minimum of 10.5% chromium content by mass.The compositions of the INCONEL alloys are different but all arepredominantly nickel, with chromium as the second element as shownbelow:

Element (% by mass) Inconel Ni Cr Fe Mo Nb Co Mn Cu 600 72.0 14.0-17.06.0-10.0 1.0  0.5 617 44.2-56.0 20.0-24.0 3.0 8.0-10.0 10.0-15.0 0.5 0.5 625 58.0 20.0-23.0 5.0 8.0-10.0 3.15-4.15 1.0 0.5  718 50.0-55.017.0-21.0 balance 2.8-3.3  4.75-5.5  1.0 0.35 0.2-0.8 X-750 70.014.0-17.0 5.0-9.0  0.7-1.2 1.0 1.0  0.5 Element (% by mass) Inconel AlTi Si C S P B 600 0.5  0.15 0.015 617 0.8-1.5 0.6 0.5  0.15 0.015 0.0150.006 625 0.4 0.4 0.5  0.1  0.015 0.015 718 0.65-1.15 0.3 0.35 0.080.015 0.015 0.006 X-750 0.4-1.0 2.25-2.75 0.5  0.08 0.01 

The fire-retardant material layer 16 and the thermally and electricallyconductive coating material layer 14 cooperate to providefire-resistance to the non-metallic aircraft component 10, i.e., thefire- and EMI-resistant aircraft component is rendered fire-resistant(i.e., able to pass the flame certification test), certifying theaircraft component for use. The fire-retardant material layer does nototherwise provide sufficient fire resistance (to pass the flame exposuretest) to the non-metallic aircraft component without the thermally andelectrically conductive coating material layer.

While manufacture of a fire- and EMI-resistant component has beendescribed, it is to be understood that an EMI-resistant only componentmay be manufactured by omitting the thermally and electricallyconductive coating material layer (not shown) and corresponding formingstep 120. The EMI-resistant only component comprises the intermediatearticle 12 including the continuous electrically conductive element 26and the fire-retardant layer 16 disposed directly on the intermediatearticle.

It is to be appreciated that fire- and EMI-resistant aircraft componentswith lightweight and effective integral fire- and EMI shieldingmaterials and methods for manufacturing the same have been provided.Non-metallic aircraft components may be rendered fire- andEMI-resistant, certifying them for use. The sandwich coating systemdescribed herein provides lightweight and effective integral fire- andEMI shielding materials for non-metallic aircraft components,eliminating the need for separate fire and EMI shielding materials thatadd weight and take up space.

In this document, relational terms such as first and second, and thelike may be used solely to distinguish one entity or action from anotherentity or action without necessarily requiring or implying any actualsuch relationship or order between such entities or actions. Numericalordinals such as “first,” “second,” “third,” etc. simply denotedifferent singles of a plurality and do not imply any order or sequenceunless specifically defined by the claim language. The sequence of thetext in any of the claims does not imply that process steps must beperformed in a temporal or logical order according to such sequenceunless it is specifically defined by the language of the claim. Theprocess steps may be interchanged in any order without departing fromthe scope of the invention as long as such an interchange does notcontradict the claim language and is not logically nonsensical.

Furthermore, depending on the context, words such as “connect” or“coupled to” used in describing a relationship between differentelements do not imply that a direct physical connection must be madebetween these elements. For example, two elements may be connected toeach other physically, electronically, logically, or in any othermanner, through one or more additional elements.

While at least one exemplary embodiment has been presented in theforegoing detailed description of the invention, it should beappreciated that a vast number of variations exist. It should also beappreciated that the exemplary embodiment or exemplary embodiments areonly examples, and are not intended to limit the scope, applicability,or configuration of the invention in any way. Rather, the foregoingdetailed description will provide those skilled in the art with aconvenient road map for implementing an exemplary embodiment of theinvention. It being understood that various changes may be made in thefunction and arrangement of elements described in an exemplaryembodiment without departing from the scope of the invention as setforth in the appended claims.

What is claimed is:
 1. A fire-and EMI-resistant aircraft componentcomprising: an article comprised of a polymeric material; afire-retardant material layer overlying the article; a conductivecoating material layer intermediate the article and the fire-retardantmaterial layer; and optionally, at least one continuous electricallyconductive element integrated with the polymeric material of thearticle.
 2. The fire and EMI-resistant aircraft component of claim 1,wherein the article includes the at least one continuous electricallyconductive element comprising an electrically conductive filamentintegrated with the polymeric material.
 3. The fire and EMI-resistantaircraft component of claim 1, wherein the at least one continuouselectrically conductive element comprises a material selected from thegroup consisting of copper, aluminum, alloys thereof, brass, andcombinations thereof.
 4. The fire and EMI-resistant aircraft componentof claim 1, wherein the conductive coating material layer is comprisedof a metal selected from the group consisting of copper, aluminum,alloys thereof, brass, and combinations thereof.
 5. The fire andEMI-resistant aircraft component of claim 1, wherein the at least onecontinuous electrically conductive element extends from a first end ofthe article to a second end of the article to provide a conduction paththrough the article.
 6. The fire and EMI-resistant aircraft component ofclaim 5, wherein the at least one continuous electrically conductiveelement is in a spiral form.
 7. The fire and EMI-resistant aircraftcomponent of claim 1, wherein the fire-retardant material is selectedfrom the group consisting of a nickel-based alloy or superalloy, aferrous-based alloy, a cobalt-based alloy, and combinations thereof. 8.The fire and EMI-resistant aircraft component of claim 1, wherein theconductive coating material layer is applied locally to portions of thearticle.
 9. A fire-and EMI-resistant aircraft component comprising: anarticle comprised of a polymeric material having a first end and asecond end; a fire-retardant material layer overlying the article; aconductive coating material layer intermediate the article and thefire-retardant material layer; and at least one continuous electricallyconductive filament integrated within the polymeric material of thearticle that extends through the article from the first end to thesecond end to provide a conduction path through the article.
 10. Thefire and EMI-resistant aircraft component of claim 9, wherein the atleast one continuous electrically conductive element comprises amaterial selected from the group consisting of copper, aluminum, alloysthereof, brass, and combinations thereof.
 11. The fire and EMI-resistantaircraft component of claim 9, wherein the conductive coating materiallayer is comprised of a metal selected from the group consisting ofcopper, aluminum, alloys thereof, brass, and combinations thereof. 12.The fire and EMI-resistant aircraft component of claim 9, wherein the atleast one continuous electrically conductive element is in a spiralform.
 13. The fire and EMI-resistant aircraft component of claim 9,wherein the fire-retardant material is selected from the groupconsisting of a nickel-based alloy or superalloy, a ferrous-based alloy,a cobalt-based alloy, and combinations thereof.
 14. The fire andEMI-resistant aircraft component of claim 9, wherein the article is aninlet duct.
 15. The fire and EMI-resistant aircraft component of claim9, wherein the conductive coating material layer is applied locally toportions of the article.
 16. A fire-and EMI-resistant aircraft componentcomprising: an article comprised of a polymeric material having a firstend and a second end; a fire-retardant material layer overlying thearticle; a conductive coating material layer intermediate the articleand the fire-retardant material layer, the conductive coating materiallayer applied locally to portions of the article; and at least onecontinuous electrically conductive filament integrated within thepolymeric material of the article that extends through the article fromthe first end to the second end to provide a conduction path through thearticle.
 17. The fire and EMI-resistant aircraft component of claim 16,wherein the at least one continuous electrically conductive elementcomprises a material selected from the group consisting of copper,aluminum, alloys thereof, brass, and combinations thereof.
 18. The fireand EMI-resistant aircraft component of claim 16, wherein the conductivecoating material layer is comprised of a metal selected from the groupconsisting of copper, aluminum, alloys thereof, brass, and combinationsthereof.
 19. The fire and EMI-resistant aircraft component of claim 16,wherein the at least one continuous electrically conductive element isin a spiral form.
 20. The fire and EMI-resistant aircraft component ofclaim 16, wherein the fire-retardant material is selected from the groupconsisting of a nickel-based alloy or superalloy, a ferrous-based alloy,a cobalt-based alloy, and combinations thereof.